Transsphenoidal hypophysectomy (by drdhiru456)

TRANSSPHENOIDAL
HYPOPHYSECTOMY
-DR DHIRENDRA V. PATIL
M.S. (ENT)
J.N.M.C., Aligarh Muslim University.

INTRODUCTION
 Pituitary tumors are commonly benign pituitary
adenomas and only rarely are pituitary
carcinomas or posterior pituitary neoplasias.
 Pituitary adenomas present most commonly in
the third and fourth decades.
 Their clinical presentation depends whether the
tumor is secreting (less common) or
nonsecreting (more common).
drdhiru456@gmail.com

 Secreting adenomas present with the
endocrine manifestations of the hormone
secreted.
 The most common is a prolactin-
secreting tumor.

CLASSIFICATION OF
PITUITARY TUMOURS
 Histological classification –
 Three types of anterior pituitary cells are
traditionally described:
 1. Chromophobe cells, which contain no
granules,
 2. Basophil and
 3. Eosinophil cells.

Functional classification :
a) Functioning Adenomas -
-prolactinoma;
-GH-secreting adenomas: acromegaly;
-ACTH-secreting adenomas: Cushing’s
disease and Nelson’s syndrome;
-TSH-secreting adenoma (TSHoma);
-gonadotrophinoma;
b) Non-functioning adenoma.

Size classification
 Practical classification for pituitary adenomas.
 Hardy described this in 1969 and it is still a
useful classification in clinical practice.
1. Microadenomas are intrasellar lesions of up
to 10mm in diameter.
These tumours will only present because they
are functioning or because they are an
incidental finding on a scan performed for other
reasons (incidentalomas).

2. Macroadenomas are tumours of greater
than 10mm in diameter.
 They may or may not be functioning, and
depending on their size and direction of spread
they may cause symptoms
3. Mesoadenomas is the term used by some
other authors for those tumours of
intermediate size (10 mm) in diameter.

 The smaller and more clearly defined
the abnormality, the better the
chance of removing it and preserving
normal pituitary function.

CLINICAL FEATURES OF
PITUITARY TUMOURS
 1. Endocrine effects –
Mainly due to the effect of the excess of
the hormone in question.
 2. Space-occupying effects –
 Superior expansion
 Lateral extension
 Inferior extension

THE ROLE OF SURGERY
IN THE MANAGEMENT
OF PITUITARY TUMOURS

Indications for
hypophysectomy
 Surgery can be carried out on the pituitary
gland for diagnostic or therapeutic
purposes.
 Diagnostic: To obtain tissue for histology
when a lesion has been identified which
cannot be classified by biochemistry and
imaging, or if histological confirmation is
required for a lesion that is not treatable by
surgery.

 Therapeutic:
To treat an identified condition, such as
a pituitary adenoma or other amenable
pathology.

Contraindications for
surgery
 General contraindications include the
following.
1. Uncontrolled disease caused by the
adenoma. An example would be poorly
controlled Cushing’s disease.
2. Poor general health. Once again the risk of
anaesthetic and surgery should be minimized.
3. Increased risk of haemorrhage.

 Local contraindications include the
following:
1. Abnormal anatomy ,
2. Sinusitis, nasal vestibulitis or other
significant nasal infections are a
contraindication because of the risk of
meningitis.

Patient information and
consent
 A detailed individual explanation is always
necessary for all patients, which should include:
1. A careful explanation of the treatment options,
2. the serious nature of the condition and the
surgery,
3. the way in which the surgery is carried out,
4. the nasal pack,
5. the importance of medication in the
postoperative period,

6. The range of outcomes following surgery.
7. The likelihood of complications, their
nature.

Preoperative
investigations
 For good surgical outcomes, the patient
should be as fit as possible preoperatively.
 ROUTINE LABORATORY
INVESTIGATIONS :
A full blood count and biochemical profile
are important as diseases of the pituitary
have widespread effects.

 PREOPERATIVE IMAGING :
 MR scan is now the most useful imaging
technique.
 T1, without and with contrast, and T2 images
are both valuable.
 Coronal CT scanning of the sinuses and
pituitary fossa provides the best bone detail,
and so if there is a need for this detail (e.g.
erosion of the clivus) this form of imaging
should be used. drdhiru456@gmail.com

 MR angiography or conventional
angiography may be used if there is any
suggestion of a vascular lesion.

 VISUAL FIELD ASSESSMENT :
 Full records of the visual fields are required
in the following circumstances:
1. if a patient with a pituitary tumour
complains of any visual disturbance;
2. in the presence of a macroadenoma with
tumour abutting on the optic nerves or
chiasm.

 Typical visual field abnormality is a bitemporal
superior quadrantanopia or hemianopia.

Preparation for surgery
 NASAL PREPARATION :
 Use of vasoconstrictors in the nose is
essential to reduce bleeding from the
nasal mucosa and improve access.
 Should include both,
1. The application of topical vasoconstriction
(e.g. xylomatazoline 0.1 percent spray) to
the nasal mucosa of both nostrils and

2. Injection of local anaesthetic agent and
adrenaline (lignocaine 2 percent with
1:80,000 adrenaline) into the nasal
mucosa.

 ANAESTHESIA:
 Patient requires general anaesthesia with
orotracheal intubation.
 It is valuable for the anaesthetist to be able
to raise the CSF pressure when requested,
to push the upper part of the gland into
the fossa during the dissection of a
macroadenoma.

 POSITIONING :
 The patient’s head must be stable but able
to be rotated to enable convenient access
to the nose with an endoscope or
microscope while the surgeon is
comfortably positioned.

EQUIPMENT
 A standard set of nasal instruments should
be supplemented with retractors that are
long enough to allow direct vision of the
sphenoethmoidal recess.
 A self-retaining retractor (Hardy retractor)
showing this view is important if a
microscope is used (Fig).

 If the surgeon’s
preference is to use a
microscope, angled
eyepieces are helpful
as they allow a more
comfortable operating
position.
 A 300-mm focal length
objective should be used.

 If Hopkins rod endoscopes are being used,
most of the surgery is done with a 0 degree
endoscope,
 Although 30 and 70 degree endoscopes are
useful for inspecting the interior of the
sphenoids and the pituitary fossa.

 For opening the pituitary fossa, Angell James,
Hardy or similar hypophysectomy instruments
may be sufficient to dissect off the mucosa and
winkle off thin bone

SURGICAL
APPROACHES

 The two main routes to the pituitary
gland are
1. Transsphenoidal and
2. Transcranial.
 Transsphenoidal route is now the
method of choice in 95 percent of
cases.

APPROACHES TO THE
SPHENOID SINUS
 Various routes for transsphenoidal
surgeries are:
1. Transseptal route.
2. Transethmoidal route.
3. Transnasal route.

1. Transseptal route
 This route follows the subperichondrial and
subperiosteal plane to the rostrum of the
vomer.
 Rostrum of the vomer is removed to gain entry
to the sphenoid sinuses.

 This plane (subperichondrial and
subperiosteal plane ) can be entered
through a submucosal resection
incision or through a sublabial
incision.

Using the sublabial incision, periosteum over the
premaxilla is incised and the piriform aperture is
exposed.

 The nasal spine is exposed and the nasal
mucosa is dissected off the anterior septum
and off the floor of the nose using a
periosteal elevator.
 The dissection has to be taken far enough
up both sides of the septum and across the
floor of the nose to allow the quadrilateral
cartilage to be displaced laterally without
tearing the mucoperiostium.

 Clear view of the rostrum of the vomer is
achieved.
 By removing rostrum of vomer an
excellent view of the area of the pituitary
is obtained in the midline.
 This view is maintained by inserting a
Hardy self-retaining retractor, which is
extremely stable.

2. Transethmoidal route
 Requires an incision from the medial end of the
eyebrow, curved round the medial aspect of
the orbit, inferiorly to the level of the upper
edge of the piriform aperture of the nose.

 A window is made in the medial wall of
the orbit by removing the lacrimal bone
in the floor of the lacrimal groove, the
posterior edge of the frontal process of
the maxilla and some part of the lamina
papyracea.
 Access is obtained through the ethmoid
complex to the sphenoid.

 The anterior wall of both sphenoid sinuses
is removed to gain an excellent view of the
pituitary fossa.
 This view is maintained using a Talbot
retractor.

 Talbot retractor for
the transethmoidal
approach in use
showing the anterior
ethmoidal artery

Transnasal route
 Nose is well-vasoconstricted.
 The middle turbinate is lateralized, the spheno-
ethmoidal recess and the sphenoid ostium are
then identified.
 The anterior wall of the sphenoid sinus is
removed inferiorly, widening the ostium, and
then similarly in the other nostril.

 An incision is made in the posterior septum
about 1 cm anterior to the rostrum of the
vomer, a subperiosteal dissection is made
of the rostrum, which is then removed.
 The rostrum is tough bone and proves
valuable if the surgeon wishes to repair
the defect in the anterior wall of the
pituitary fossa with bone.

 The transnasal route is now the
preferred approach because it is
quick, is suitable for use with the
endoscope and causes least
morbidity.

INDICATIONS FOR
TRANSCRANIAL APPROACH TO
THE PITUITARY GLAND
 Large intracranial element of the tumour
that is unlikely to be accessible during
transsphenoidal surgery, then this approach
should be considered.

Endoscopic
Transsphenoidal
Hypophysectomy

 Major reason for developing endoscopic
pituitary tumor resection techniques is to
minimize intranasal complications
and to provide superior visualization.
 The endoscopic view is panoramic
when compared with the microscopic
view.

 In addition, angled endoscopes allow
tumor that extends outside the sella to
be seen and this improves the surgeon’s
ability to achieve complete tumor
resection.

Surgical Technique
 Patients are catheterized prior to surgery.
 This allows manipulation of fluid balance
during surgery and allows the patient’s
postoperative urine output to be
monitored.
 Standard preparation of the nose is
performed with topical vasoconstriction and
infiltration.

 Any significant septal deviation is dealt with
via either a Killian or Freer
(hemitransfixion) incision.
 The endoscope and microdebrider are
passed medial to the middle turbinate and
the superior turbinate and often the
sphenoid ostium are identified (Fig)

 The next step is to remove bilaterally the lower
two-thirds of the superior turbinate and expose
the natural ostium of the sphenoid sinus (Fig)

 The sphenoidotomies are enlarged up to
the lateral wall of the sphenoid.
 The access provided should allow passage
of an instrument below the pituitary fossa
and laterally onto the internal carotid
artery and optic nerve eminences. (Fig)

 The next step is to remove the sphenoid
mucosa starting on the sphenoid septum
in the larger of the two sinuses.
 The sphenoid sinus septum is removed
flush with the pituitary fossa (Fig)

 The thin bone
of the anterior
face of the
pituitary is
fractured and
removed with a
Kerrison punch
(Fig)

 A no. 11
scalpel blade
on a no. 7
BP handle is
used to
create an U-
shaped
incision into
the dura
(Fig)

 Malleable suction ring curettes and
standard pituitary ring curettes are used
to first clear the tumor along the floor of
the pituitary fossa until the posterior
wall of the pituitary fossa is seen (Fig)

 Once the tumor has been completely
removed, Gelfoam paste (Gelfoam
powder mixed with saline to form a paste) is
placed within the pituitary fossa.
 The preserved dural flap and sphenoid
mucosa are positioned over the anterior face
of the sella and fibrin glue applied to the
surface (Fig)

 The middle turbinates are repositioned in
their correct orientation and the operation
is complete.
 If the patient has a CSF leak from the
diaphragm, then the hole in the diaphragm
is identified and a conically shaped fat
graft is placed into the defect and gently
pushed through the hole with the malleable
probe until the leak is completely sealed.

COMPLICATIONS OF
SURGERY
 Intraoperative complications :
1.haemorrhage,
2. CSF leak.
 Early postoperative complications :
1. Diabetes insipidus,
2. CSF leak,
3. Meningitis (unusual).

 Late postoperative complications :
-Persistent diabetes insipidus.
-Nasal and sinus complications.
-Recurrence of the tumour.

THANK
YOU
-drdhiru456@gmail.com

Transsphenoidal hypophysectomy (by drdhiru456)

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